1. Field of the Invention
This invention relates to vent pipe coverings, and, more particularly, to coverings for vent pipes extending through roof structures on top of which will be applied insulation.
2. Description of the Prior Art
In general construction, vent pipes, as for plumbing fixtures, extend through the roof structures of the building and upwardly therefrom. They are sealed, appropriately, with flashing, etc. Generally, for relative large buildings, or homes, several vents are ganged together, and a single pipe extends through the roof. In some cases, the vents are covered above the roof to prevent rain, etc., from flowing downwardly through the vent. For other applications, the vents are open, because rain, debris, such as leaves, etc., are not a problem.
For different types of structures, such as mobile homes, the wall structure is relatively thin and each plumbing unit accordingly has its own vent pipe extending upwardly through the roof. The wall structures in such buildings are not large enough, or thick enough, to allow for the ganging of multiple vents, and each unit accordingly has its own vent pipe. Due, in part, to the wall structure, the vent pipes in such buildings are relatively small, or narrow in diameter, and it is accordingly preferred that the vents are shielded above the roof line. It is not untypical for the vents and their protective coverings to extend above the roof line only a very few inches.
Due to the lack of attic space in mobile homes and other, similar structures, only a limited amount of interior insulation is disposed beneath the outer roof covering. The amount of insulation is not sufficient to adequately protect the structure against the intrusion of outside heat in the summer time, or to prevent the loss of interior heat during cold weather. A way of overcoming the lack of interior insulation is to insulate the structure from the outside, as by using flexible or other exterior insulation. Such flexible, exterior insulation is disclosed in U.S. Pat. No. 4,045,922, dated Sept. 6, 1977.
For vent pipes that extend several inches above a roof structure, the insulation is simply sealingly secured about the outer periphery of the vent pipes. When the vent pipes extend upwardly above the exterior insulation, there is generally no further problem. However, when the exterior insulation, such as the flexible insulation disclosed in the U.S. Pat. No. 4,045,922 patent, is secured to a roof through which a vent pipe extends only a very few inches, and where the thickness of the exterior insulation will extend above the original vent, then the vent pipe must be extended, and additional protection must be given to the vent pipe and to its extension.
Heretofore, the sealing of flexible insulation to metal vent pipes has been accomplished primarily in the manner discussed in the U.S. Pat. No. 4,045,922 patent. However, when a vent pipe is made of a polymerized product, such as PVC, ABS, or ABS-DWV, various problems arise. One of the problems is the susceptibility of PVC, and various other polymerized materials, to ultraviolet radiation. The ultraviolet radiation, as from sunlight, causes the PVC material to deteriorate and accordingly to crack, etc.. When exterior insulation is sealingly secured to such PVC pipe which has aged under ultraviolet radiation, a repairman or other person who walks on the roof, and accordingly on the exterior insulation, risks damaging the vent pipe due to the stresses imposed on the vent pipe by the insulation secured thereto.
The apparatus of the present invention overcomes problems of the prior art. It comprises a protective cap made of metal which covers the vent pipe and gasket material which sealingly secures to the insulation material, such that movement of the exterior insulation, and the stresses associated therewith, are not transmitted to the vent. It thus prevents damage to the vent and to the insulation. Moreover, the vent apparatus provides protection for the vent pipe by shielding the pipe from damaging ultraviolet radiation. The original vent covers are removed prior to the installation of the apparatus of the present invention.